CNTNAP2 and Cortical dysplasia - focal epilepsy syndrome: A third syndromic gene affected by a deletion in our sample is CNTNAP2. Homozygous or compound heterozygous mutations in CNTNAP2 are the cause of cortical dysplasia-focal epilepsy syndrome (CDFES; OMIM 610042) and this gene has been implicated in multiple neurodevelopmental disorders, including autism and ID22.